Why You Can Trust CNET Boost Your Health and Wallet: The Power of Intermittent Fasting
Intermittent fasting may seem challenging, but with practice, you can get used to it and experience both the health and financial benefits.
You've probably heard about intermittent fasting, since it's arguably one of the hottest health trends from the last couple of years. It's been heralded as not only a foolproof weight-loss method, but also as a potential cure for conditions like high cholesterol, high blood pressure, poor sleep, insulin resistance, cancer and Alzheimer's disease. A 2019 study in The New England Journal of Medicine specifically connects intermittent fasting to "increased stress resistance, increased longevity and a decreased incidence of diseases, including cancer and obesity."
Want to learn more and perhaps try intermittent fasting yourself? Here's everything you need to know, including some of my own experiences with it. If you want to try it out for yourself, you should always consult a doctor before changing your diet or eating behaviors.
Read more: Is Intermittent Fasting Actually Dangerous? How to Know If Time-Restricted Eating Is for You
What is intermittent fasting?
Most of us eat throughout the day, starting with breakfast when we wake up and perhaps ending with a dessert after dinner. If you have breakfast at 7 a.m. and a final treat at 8 p.m., you're consuming food for 13 hours; that's your current "eating window." The idea behind IF is simply to shorten that window -- not necessarily to eat less (though of course that's part of it), but to eat less often.
A common intermittent fasting plan includes an 8-hour eating window, meaning a 16-hour fast. So you could have lunch at noon and still finish your snack by 8 p.m. That's it. If you can stick to that, it may be enough to produce results.
But wait, isn't that just skipping breakfast? Haven't we heard for years that skipping breakfast actually leads to weight gain? Yes, and yes. However, IF requires a "clean" fast to be effective (more on that below), and once you get accustomed to it, your appetite should correct so that you no longer overeat once your window opens.
Here's what I love about this: It costs nothing. It requires nothing. You don't have to buy books or gear or supplements or meals. You just adapt yourself to a slightly different way of eating (or "WOE," unfortunate though that sounds) and that's it. The simplicity -- and affordability -- of IF is what drew me to it.
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The best part about intermittent fasting
Gin Stephens is the author of Delay, Don't Deny: Living an Intermittent Fasting Lifestyle. Those first three words of the book title are the key to what makes this WOE worthwhile: You're not denying yourself anything, you're merely delaying it. You don't have to give up pizza because of the carbs or ice cream because of the sugar. You just have to wait until your window opens; then you can eat what you want. No, not the entire pizza or a whole pint of ice cream; you still have to be reasonable. But there are no exclusions, and that's incredibly liberating.
Think about nearly every other diet in history: Atkins, South Beach, paleo, keto. They all require you to cut out certain food groups entirely (fat, carbs, sugar) or eat excess food types (protein, cabbage soup). The reason these diets typically fail is they're not sustainable.
Stephens is fond of the saying: "Diets are easy in contemplation and hard in execution. Fasting is hard in contemplation but easy in execution." She comments further, stating, "I absolutely love that quote because it's so true. We've all started a new diet and we're all in. Then, as the days go by, the diet gets harder and harder to stick to. Intermittent fasting is the exact opposite. Instead of getting harder and harder, it gets easier and easier."
The intermittent fasting benefits no one talks about
Lost amid the talk of intermittent fasting's health benefits is a very real secondary perk: saving money. When you cut your diet down to one or two meals per day, your food costs drop accordingly. It's impossible to say exactly how much you stand to save because it depends on how often you dine out, what you buy at the grocery store and so on.
However, even if your total food expenses drop by just 25%, that's a huge difference. Suppose you typically spend $100 per week on food. If you subtract the cost of seven meals per week, that might lower your weekly food expense to $70. Over the course of one month, you'd save $120, and over one year, $1,440.
That's a vacation or a down payment on a new car. Plus, there's a bigger-picture benefit as well: You're lowering your impact on the environment. Imagine if entire populations switched to two meals a day from three. We could get by on fewer crops and animals, which in turn would reduce overall water consumption. Maybe that's a bit of pie-in-the-sky thinking, but there's truth to it.
Read more: The Most Environmentally Friendly Meal Kit Is Also the Best
I mention all this because after I started IF, I noticed I was spending less on food. Then, I started thinking about the external benefits of less food consumption, which made me feel even better about it. Eat less, help the planet. Win-win!
You might have to give up late-night snacking with IF.
How to start intermittent fasting
There are multiple schools of thought regarding how to schedule intermittent fasting. The Fast Diet is fairly different from what's described above; it's commonly known as 5:2, meaning you eat normally five days a week and fast for two. That may work for some, but two days of restricted eating doesn't sound very appealing.
I prefer the daily method: Fast for at least 16 hours per day. The aforementioned New England Journal of Medicine study was based on an 18:6 structure: 18-hour fast, 6-hour eating window.
"16:8 is a great place to start," Stephens says, "but it may not be a weight-loss window for many people. That's because fat-burning ramps up between hours 18 and 24 of the fast. 19:5 was a great weight-loss sweet spot for me, and I lost about a pound per week when doing it. With 19:5, you fast for 19 hours a day and have an eating window of 5 hours. Your sweet spot may be different from mine, of course. Maybe it will be 18:6 or 20:4." Experimentation is key, she adds.
Before you embark on this journey, I recommend reading CNET writer Caroline Roberts' guide to doing intermittent fasting safely.
If your eating window doesn't include breakfast, you can still drink coffee as long as it's black and unsweetened.
A clean intermittent fast
The most important part of the equation is not the length of the window; it's the fast itself, which must be entirely "clean," according to Stephens. That means water, coffee and tea only, with absolutely no added fat, artificial sweeteners or the like. No bone broth, no water with lemon, no flavored teas. No gum, no mints, nothing with calories, period. The goal is to deprive your body of anything that triggers insulin production, because an insulin-deprived body turns to fat stores for energy.
One of the toughest hurdles for many people is giving up cream and sugar in their coffee. I was always a sugar man; when I made the switch to black coffee, it sucked for maybe a week or so. Now I'm a convert; I actually like it better.
Stephens can't stress enough the importance of following the clean-fast rule. "For anyone who has ever tried IF in the past but was not fasting clean, now you know why it was so hard for you. The clean fast is so much easier, I promise."
Intermittent fasting resources
Stephens has a new book -- Fast, Feast, Repeat: The Comprehensive Guide to Delay, Don't Deny Intermittent Fasting -- that offers "a deeper dive into the science" than her first one. In the meantime, she recommends two other titles: The Obesity Code by Dr. Jason Fung and AC: The Power of Appetite Correction by Dr. Bert Herring.
There's also a Facebook group, Delay, Don't Deny: Intermittent Fasting Support, that's an offshoot of Stephens' first book. It boasts over 300,000 members who ask and answer questions, and share stories and encouragement. You'll also find many before-and-after photos illustrating exactly how effective IF has been for some.
But not for all. You'll also see posts along these lines: "I fasted clean for two months, ate one meal a day and didn't lose a single pound." Others will note that it took them six months before the scale started to budge. "It takes time," Stephens says. "We didn't become overweight and unhealthy overnight, and it takes time to reverse these health conditions. Once your body has begun healing, fat loss is more likely." How long that takes depends on various factors, including age, sex at birth, starting weight and more.
My experience with intermittent fasting
I started IF in August 2018. At the time, I weighed around 181 pounds, which is acceptable for a 6-foot male. But I'd been 175 pounds for years, and suddenly it seemed I couldn't control my eating. I didn't like where my belly was headed.
After about two months, when my fasting windows varied (but averaged around 17:7), I'd lost 10 pounds. Needless to say, I was pleased with that result and became pretty evangelical about intermittent fasting. My excitement stemmed from not only the weight loss, but also the total lack of hardship. This didn't feel like a diet; it felt like a smart way to live.
In fact, I discovered that I really liked this way of eating. When I was feeling a little hungry in the late morning? Just wait a bit longer, I told myself, your window opens soon. Then I'd busy myself with something and forget about it. And if I wanted a snack after 7 p.m.? Too bad, the window's closed for the day -- but you can have it tomorrow.
I stuck with intermittent fasting for about 10 months, though I'll admit I got frustrated at times. For one thing, I'd been hoping to lose another 5-10 pounds, and assumed they'd come off as easily as the first 10, but the scale held firm at 171.
Meanwhile, there were times when it was much harder to manage my window, like during family vacations when we'd all eat later than usual and breakfast was a part of the experience. Then came the holidays, various parties and family gatherings, which also presented window-related challenges. With a little planning, it's possible to adjust to these things, but ultimately I just got lazy about it -- probably because I'd lost the weight I'd initially wanted to lose.
Over the summer, I decided to pump the brakes. However, six months later, the scale once again showed 180. (Actually, 182 this time.) So in January 2020, I went back to IF, and once again, I'm really liking the simple discipline. I now do 18 hours on average. When I get to around 16 hours and start to feel a little tired or hungry, I hop on the elliptical or go for a run. By the time I'm done, showered and have made myself lunch, it's no trouble hitting 18 hours. Sometimes I stretch my fasting to 19 or even 20 hours.
Result: After four months (almost to the day), the scale shows 171. (One piece of advice, though: Stay off the scale. Weigh yourself once a month, tops. Otherwise, that thing will drive you nuts because weight fluctuates.) In the interim, I've eaten an almost embarrassing amount of food while my window was open. I don't have a sugar monkey on my back; I have a sugar gorilla. Nevertheless, I'm thinner and will see if I can hit 165 pounds. This lifestyle -- not diet, mind you -- is a piece of cake. Speaking of which, I think I'll go have one of those.
Whether you're fed up with diets or just want to improve your overall health, intermittent fasting is absolutely worth a try. It costs nothing to do and can actually save you money while maybe even helping the planet.